Steering gear



N0V 17, 1953 L. E. oBERHoLTz ET Al. 2,659,613

STEERING GEAR Filed April l5, 195] INVENTOR. e5/er ero/fz awa/ 5,6/7@ /4//6/7 WM +M.

Patented Nov. 17, 1953 STEERING Lester E. Oberho'ltz and Gene, Allen, Independence Mo., assignors to Gleaner Harvester Oorporation, Independence, Mo., a corporation of Delaware Application April 13, 1951, Serial No. 220,912.

1 Claim.

This invention relates to a self-propelled combine or similar mobile machine which must be kept stable on irregular ground. Such machines are best supported on at least four wheels but a tri-point suspension is required between the whee1s` and body of the machine to avoid twisting and racking stress in the super-structure and to provide stability'. Consequently, one ofv the axles is fixed While the other is adapted to rock with respect to the super-structure. Such an arrangement solves the supporting problem but it has been difficult to provide a steering mechanism for theI wheels of the pivotally mounted axle.

It is therefore the principal object of the present invention to. provide a steering mechanism for self-propelled combines and similar machines which is easy to steer and which is not aiTected by movement of thel axle with respect to the super-structure of the machine on- Which, a part of the steering apparatus is supported.

It is a further object of the invention to provide a steering mechanismwherein the leverages remain substantially constant regardless of the positions. of the pivotal axle.

In accomplishing these and other objects of the invention as hereinafter pointed out, we have providedA improved structurey the preferred form of which is illustrated in the accompanying drawing wherein:

Fig. 1 is a side elevational view of:A a selfpropelled combine equipped with ay steering mechanism-- constructed inaccordance with the present4 invention for steering the rear wheels,

the nearest of the rear wheels; being showrr're- 'Y moved to better illustrate the steering mechanism.

Figa 2 is a fragmentary plan View of' a rear portionv of the combine frame; rear axle; and the journal mounting of the axle, the journal mounting being shown in section to better illustrate the portions of the steering mechanism extending therethrough.

Fig. 3 is a perspective View of the steering mechanism shown in full lines with the axle and i i forward portion of the main frame is carried Cl l) on main traction wheels- 8' that' are carriedin spaced apartl fixed' relation with respect to the ma-in frame so that the forward portion of the harvesting unit is kept in parallel relation with the ground over which the machine is propelled; The rear; portion 9` of the frame is carried' on an axle I0 having a journal connection II at the center thereof and' withv the rear portion of the main frame whereby the. rear axle may tilt to maintain the Wheels` l2 thereofin Contact .with the ground while the traction Wheels andlOurnal mounting Il form a tri-point support ofthe frame to avoid stresses and strains in. the above describedl operating mechanisms of the machine.

In` the illustrated instance,r the main frame includes parallel side rails I3, and |'4 that are connected at their rear ends. by aA cross rail" I5 and rearwardly converging rails i6, and I'T that are interconnected by a bracket I8 carrying a bearing I-9 in rearwardly spaced coaxial relation with a similarbearing 2l)y that is carried` by the cross rail 15. The, bearings are thusk carried in the longitudinal center line of the machine .and mid-way between the front Wheelsl Extending through the bearings I andz20 is atubular. journal IA that is adapted; tok oscillate in therespective bearings and which has its rear endextendingthrough the axleA lll and. welded securely thereto as indicated' at 22, whereby .thevjournal and axle oscillate as a unit on a horizontal axis. Inserted between the bearing I9. and the axle and preferably welded to. the axle as,- indicated at- 23 is a thrust collar 24 which, cooperates with a collar 25 engaging the forward end of the bearing l'9 to preventlongitudinal or axial move.- ment' of the tubular journal within, the. bearings It or 20; The collar 251 is secured tothevjournal by; fastening devices such as. bolts26 that', extend throughv suitable registering openings. 21 in .the collar andthe journal' las shown in Fig. 2. The axle ID may be a box-like section to provide a solid connection with the journal and the necessary rigidity in the axle structure. The axle extends beyond the ends of the side rails of the main frame and the ends thereof mount steering knuckles 28 and 29 carrying spindles 30 and 3| f'or rotatably mounting the rear wheels l2 thereon. The steering knuckles carry rearwardly extending arms 32 and 33 that are pivotally connected as at 34 and 35 with tie rods 36 and 31 which have their inner ends overlapping and pivotally connected with a bell crank 38 by means of pivotal connections 39 and 40 substantially in the manner as a conventional center point steering mechanism. The bell crank 38 has one arm 4I xed to a yoke 42 that is pivotally connected with the axle at one side of the tubular journal by a pin or bolt 43. The other arm 44 of the bell crank curves forwardly toward the center of the axle and enters the open rear end 45 of the tubular journal Il as best shown in Fig. 2. Extendingzthrough the tubular journal is a drag link 46 khaving ball and socket connection with the arm 44 as indicated at 41. The opposite end of the drag link 46 is connected by similar ball and socket joint 48 with a rocker arm 49. The rocker arm 49 is pivotally mounted as at 50 on a bracket 5I that is fixed to the cross rail I5 at a point intermediate the tubular journal and the side rail I3 of the main frame.

'I'he rocker arm 49 operates through a slot-like opening 52 in the side rail I3 and is connected by a ball and socket joint 53 with a link 54. The link 54 is in turn connected with a rocker arm 55 that is pivotally mounted on an upright 56 of the main frame on a pivot pin or bolt 51 that extends laterally from the upright so that the rock lever 55 is mounted at the side of the separator housing with one arm 58 thereof extending upwardly to connect with a drag link 59 by pivotal connection 60 while the other arm extends downwardly to connect with the link 54 through a ball and socket connection 6I. The link 59 is in turn connected by a crank arm 62 which is mounted on a rock shaft 63 carried under the platform 1. The rock shaft 63 is operatively connected with a gear reduction mechanism indicated by the housing 64 and is actuated by a steering wheel 65 mounted on a steering post 66 as in conventional practice.

With this arrangement it is obvious that the axle I0 may pivot relatively to the main frame without effecting the position of the rear wheels I2 because the connection between the parts of the steering mechanism that are carried by the main frame and those connected by the axle oper- 55 by means of the drag link connection 59 which, r

in turn, rocks the lever 49 through the drag link 54 vso as to effect reciprocatory movement of the drag link 46 through the tubular journalfor swinging the bell crank lever on the pivot 43. T he movement of the bell crank lever 38 on its yoke produces a similar movement of the knuckle arms 32 and 33 through the tie rods 36 and 31 so as to simultaneously turn the Wheels I2 and eiect desired turning movement of the machine. During this steering operation, the axle I 0 is free to rock with respect to the frame so that there is no strains or stresses applied to the Working mechanisms of the machine through the main frame or to the various steering members composing the steering mechanism.

From the foregoing, it is obvious that we have provided a steering mechanism which is composed of simple levers and link connections and which is adapted to operate the steerable ground wheels of a combine or similar machine through the tubular journal mounting for the axle which carries the wheels.

What We claim and desire to secure by Letters Patent is:

In a combine including a frame, wheels supporting the fore part of said frame at the sides thereof, a transverse axle having pivotal mounting on a rear part `of the frame at a point mid- Way of the width of the frame, steering knuckles on the respective ends of the axle and having steering arms, wheels carried by the steering knuckles, said pivotal mounting including a tubular trunnion having one end extending through the axle and the other end journalled on the frame, a bell crank pivotally mounted on the axle and having an arm registering with the end of the tubular trunnion which extends through the axle, links connecting the bell crank with said Wheels mounted on the ends of the axle, and a steering mechanism including a drag link freely reciprocable through the trunnion and connected with said arm lof the bell crank to effect steering of said wheels on the end of the axle, said steering arms, drag link and connecting links being substantially in a common plane extending through the axis of the trunnion on which the axle pivots.

LESTER E. OBERHOLTZ. GENE ALLEN.

References Cited in the ille of this patent UNITED STATES PATENTS Number Name Date 894,060 Ruemelin July 21, 1908 1,208,062 Wheelock Dec. 12, 1916 1,231,292 Parrett June 26, 1917 1,308,890 Coleman July 8, 1919 1,359,739 Prescott Nov. 23, 1920 1,677,419l Wagner July 17, 1928 2,223,274 Tait Nov. 26, 1940 FOREIGN PATENTS Number Country Date 364,054 Italy Oct. 21, 1938 

